Autisic traits link to hormone

Researchers have associated a high level of testosterone in foetuses with a raised risk of developing autism.

An eight-year study by a team at the University of Cambridge examined the development of 253 children and the amount of the hormone they came into contact with whilst in the womb.

The team looked at samples of foetal testosterone taken from women who had undergone diagnostic tests. The researchers then tracked the progress of the babies at 12, 18 and 46 months.

The team rested the children's autistic traits by, for example, measuring how many times a child looked at its mother. They found a link between levels of testosterone in the womb and autism.

They also tested the children at the age of eight by asking their mothers to answer questions from the autism spectrum quotient (a test which shows if a child has autistic traits).

The test results were then cross-referenced with the recorded womb testosterone levels.

Bonnie Auyeng, who was involved in the study, said: "The correlation is not perfect, but foetal testosterone will account for about 20% of the variability in [questionnaire] scores. Although this doesn't sound like a very high number, it is statistically significant."

However, she stressed the team were "still in the early stages of figuring out what actual role foetal testosterone plays. We don't know if it is causing autistic traits."

The team plan to examine the direct connection between autism and foetal testosterone levels, using Denmark's foetal hormone samples and its psychiatric records.